A Call for Modern Audio Codec

We need a proper audio codec to accompany state of the art video codecs, so here’s an outline of codec features that should be present:

  • audio codec should make more of its context, it should have a system of forward and backward reference frames like B-pyramid in H.264 or H.265;
  • it should employ tonal compensation with that — track the frequency changes from the references (e.g. it may be the same note continued or changing pitch);
  • time domain prediction via FIR or IIR filters;
  • flexible subdivision into subframes like binary tree;
  • raw (or non-transformed at least) coding mode for transients or noise;
  • integer only bitexact transform that passes for MDCT under bad light;
  • high-bitdepth sound support (up to 64 bits per sample).

The project name is transGhost (hopefully no Monty will be hurt by this).

And if you point out this is stupid — well, audio codecs should have the same rights as video codecs including PTS/DTS differences and employing similar coding methods.

2 Responses to “A Call for Modern Audio Codec”

  1. Tom says:

    I’m no audio codec expert, but I thought the Opus Codec was a really good audio codec. Why not use that one to accompany your video?

    Okay, perhaps it doesn’t have all the features you mention, but why do you need them so bad anyway? On the other hand, the quality is great, it is an open format, you don’t have to spend years developing something new, and if its really about maximizing your compression ratio, the audio stream’s footprint is a lot smaller than the video footprint anyway so there’s not much to gain there… No?

  2. Kostya says:

    Those are all valid points but they are completely inapplicable here. It’s about having an audio codec that matches video codec in features. Like MPEG-4 video with all its features (including synthetic 3D scene coding) was perfectly matched by MPEG-4 audio (including synthetic audio a bit like MIDI).

    Besides, Opus is close in features to Daala and I talked about H.265/VP9 companion.